this tutorial was sent to rust
by Joel Caesar. I'd like to thank him for helping us out.

Some people have problems with the Areaportal entity in Quake
2. Usually, they can get an Areaportal setup, and compiling
correctly (no errors of the "doesn't touch two areas",
or "touches more than two areas" variety). Still, the
infamous hall of mirrors effect will appear. Sometimes it even
appears on a previously working Areaportal, after you've added
another.

Here is a tip to put into your arsenal, to make more or less
perfect areaportals. Actually, it's also a door design technique.
You need to isolate the door. Completely. Take a look at the
accomanying graphic. Here you see a door between two rooms. This
could be a door between a room and a hallyway, or between two
DIFFERENT hallways. Many people when creating an Areaportal,
actually wind up putting the Areaportal touching two areas, say 1
and 2, but frequently put the areaportal within one of these
areas. Therein lies the problem.

An Areaportal, I find, has to be BETWEEN two areas, not part
of either. Sometimes the HOM effect won't appear with just two
portals, but when you have 6 or 7 (like on my map) it eventually
happens. Create a box to contain your door. Cut out the hole for
the door, being sure to leave some brush on all sides (except the
walkway of course). When you create the door, be sure it won't
touch the adjacent rooms, and is inset a little. Put the
areaportal within the door. You can let it extend into the
surrounding brush, but don't let it touch the void.

That's it. I have yet to create a door using this technique,
with an areaportal, and get the hall of mirrors effect. This
works for anykind of door, even rotating ones, and multisegmented
doors too. There may be those who say you don't need to do this
exactly like this, and sometimes I think that's true, but I find
this one so far, has worked 100% of the time for me.

Well anyways if you still don't understand please post your questions to the discussion
board.